Clinically, MIH can create serious drawbacks for the dentist as well as for the child affected. For dentists, the problems are related to unexpectedly rapid caries development in the erupting first permanent molar and unpredictable behaviour of apparently intact opacities. Moreover, these teeth are very sensitive and often require extensive treatment since rapid breakdown of tooth structure may occur, giving rise to acute symptoms and complicated treatments. Defected enamel teeth require complex treatment solutions and the different treatment options will depend on the extension of the defect, the degree of tooth eruption, the oral hygiene and diet habits of the patient. To our knowledge prevalence of MIH has not been fully discussed nor investigated in India therefore this study designed to investigate the prevalence of MIH in school going children in Nanded District.